Cardiac topics

Question 1

What ECG leads are associated with RV MI?

Answer 1

Inferior leads
- STE in V1, ST depression in V2 and STE III > II are indicators.
- Diagnosis confirmed in right precordial ECG with STE > 1mm in V4R or >0.5 in V4R and V1

Question 2

What is the usual perfusion of the RV?

Answer 2

RCA via RV marginal branches

Question 3

Which parts of the RV does the LAD typically supply?

Answer 3

• RV apex
• Anterior IV septum
• Part of the RV anterior wall adjacent to the septum
• In 15-20% a dominant LAD will result in a larger proportion of the RV free wall being supplied by the left sided circulation

Question 4

What are the principles of management in heart failure after RVMI?

Answer 4

1. Revascularisation
2. Optimise RV preload
3. Decrease RV afterload
4. Maintain perfusion pressure (MAP > 65)
5. Control arrhythmias
6. Mechanical circulatory support

Question 5

How to optimise RV preload in patients with RF failure?

Answer 5

RV is sensitive to both volume depletion and overload.
1. Caution flui bolus and observe response - if CVP increases and BP doesn’t then stop volume resus.
2. If CVP raised and signs of congestion then cautious diuresis should be trialled
Avoid drugs that decrease preload - e.g. nitrates and opiates

Question 6

How do you decrease RV afterload?

Answer 6

1. Correct hypoxaemia, avoid high PEEP
2. Consider iNO or prostacyclin